This invention relates to compositions that exhibit water and oil repellency characteristics. This invention further relates to fibers, films, fabrics, coatings, and molded or blown articles comprising the compositions. In other aspects, this invention also relates to processes for imparting water and oil repellency characteristics to substrates, to a topical treatment composition for use in at least one such process, and to certain novel fluorochemical additives for use in the compositions and processes.
Synthetic polymeric fibers have been used to make a variety of products, including carpets, drapery material, upholstery, and clothing. Often, however, such fibers (and the resulting products) have suffered from an inherent lack of water and oil repellency. Since fluorochemical groups are characteristically hydrophobic and oleophobic, various fluorochemicals have been developed for application to the polymeric fibers to impart water and oil repellency (as well as soil resistance) thereto. These fluorochemicals have most often been applied topically (for example, by spraying, padding, or finish bath immersion), but some fluorochemicals have also been useful as polymer melt additives.
In order for a fluorochemical to have utility as a polymer melt additive, it must be sufficiently thermally stable and non-volatile to withstand typical melt processing conditions. It must also be compatible with the polymer at the melt processing temperatures (to enable blending) and should preferably be able to migrate to the polymer surface as the temperature is lowered, so as to minimize the amount of fluorochemical needed to modify surface properties. This preference for migration capability has tended to limit the size of the fluorochemical molecule that can be utilized, effectively eliminating high molecular weight polymeric fluorochemicals from consideration.
Since some synthetic polymers such as polyesters require extremely high melt processing temperatures (for example, in the range of about 250-300xc2x0 C.), it has been difficult to find fluorochemicals that are not only compatible with such polymers and capable of migration within them, but that are also sufficiently thermally stable. Although useful topical fluorochemical treatments have been developed, such treatments have often lacked the durability needed for some applications (for example, clothing, carpets, and upholstery), have tended to provide uneven or non-uniform coverage, and have often involved the use of environmentally unfriendly solvents. Even if water-based topical treatments are utilized, expenses are incurred for the purchase and maintenance of coating equipment.
Thus, there remains a need in the art for fluorochemicals that can successfully function as melt additives for high-melting polymers such as polyesters. Such fluorochemicals should not only be compatible with the polymers and able to meet the stringent thermal stability requirements, but should also be able to impart durable, uniform water and oil repellency properties to the polymers for, preferably, about the same cost as topical treatments.
Briefly, in one aspect, this invention provides a water- and oil-repellent composition comprising
(a) a repellency-imparting, fluorochemical composition comprising at least one fluorine-containing aromatic ester oligomer comprising
(1) at least two polymerized (repeat) units derived or derivable from the reaction of at least one dicarboxylic acid (or a derivative thereof, for example, a dicarboxylic acid halide, a dicarboxylic acid anhydride, or a dicarboxylic acid ester) and at least one polyol, with the proviso that at least one of the dicarboxylic acid (or derivative) and the polyol is aromatic or heteroaromatic (that is, either the carbonyl moiety of the carboxylic acid groups of the dicarboxylic acid, or the hydroxyl groups of the polyol, or both are bonded directly to at least one aromatic or heteroaromatic ring (xe2x80x9cdirectly ring-bondedxe2x80x9d)) and
(2) fluorochemical endgroups derived or derivable from the reaction of
(i) the dicarboxylic acid (or derivative) and at least one fluorine-containing monoalcohol or
(ii) the polyol and at least one fluorine-containing monocarboxylic acid (or derivative); and
(b) a treatable substrate; with the proviso that,
when the treatable substrate comprises a mixture of at least two polymers, the mixture is non-stratifying.
As used herein, the term xe2x80x9coligomerxe2x80x9d means a polymer molecule consisting of only a few (for example, from 2 to about 20) polymerized (repeat) units, and the term xe2x80x9cnon-stratifyingxe2x80x9d means that the polymers in a polymer mixture are sufficiently compatible that a melt blend thereof does not phase separate to form two or more polymeric layers of different composition. Preferably, the polyol is a diol, and the treatable substrate comprises at least one thermoplastic or thermoset polymer (more preferably, a thermoplastic polymer; even more preferably, a thermoplastic polymer having a melting point above about 150xc2x0 C.; most preferably, a polyester).
It has been discovered that the above-described, aromatic ester oligomer-containing, fluorochemical composition can be used to impart water and oil repellency, soil resistance, solvent resistance, and release properties to a variety of substrates. The substrates can be treated either by topical (external) application of the fluorochemical composition or by using the fluorochemical composition as a melt (internal) additive. Surprisingly, in spite of its higher molecular weight component(s), the aromatic ester oligomer-containing fluorochemical composition provides repellency properties comparable to or better than those imparted by the corresponding monomeric composition (containing only aromatic ester monomer(s) or compound(s)). Such repellency properties can thus be achieved without the need for careful molecular weight control.
In addition, certain preferred embodiments of the fluorochemical composition (for example, those comprising aromatic ester oligomer(s) having sulfonamido-linked fluorochemical endgroups) exhibit exceptionally high thermal stabilities (being stable at temperatures up to, for example, about 300xc2x0 C.). These embodiments are thus particularly well-suited for use as melt additives for thermoplastic polymers and, in particular, meet the need in the art for fluorochemicals that can successfully function as melt additives for high-melting polymers such as polyesters and polyamides. The preferred fluorochemical compositions are not only compatible with such high-melting polymers and able to meet their stringent thermal stability requirements, but they are also able to impart durable, uniform water and oil repellency properties to the polymers for about the same cost as topical treatments.
In other aspects, this invention also provides fiber, fabric, film, a coating, and a molded or blown article comprising the water- and oil-repellent composition of the invention; processes for imparting repellency characteristics to a substrate, for example, by bulk addition or by topical treatment; a topical treatment composition comprising (a) the above-described repellency-imparting, fluorochemical composition and (b) at least one liquid, organic or aqueous vehicle; and a novel repellency-imparting, fluorochemical composition comprising at least one fluorine-containing, aromatic ester compound or oligomer comprising (a) at least one repeat or repeatable unit derived or derivable from the reaction of at least one dicarboxylic acid (or a derivative thereof) and at least one polyol, with the proviso that at least one of the dicarboxylic acid (or derivative) and the polyol (that is, either the dicarboxylic acid or the polyol or both) is aromatic or heteroaromatic and (b) sulfonamido group-containing, fluorochemical endgroups derived or derivable from the reaction of (i) the dicarboxylic acid (or derivative) and at least one fluorine-containing, sulfonamido group-containing monoalcohol or (ii) the polyol and at least one fluorine-containing, sulfonamido group-containing monocarboxylic acid.
Fluorochemical Composition
The repellency-imparting, fluorochemical composition used in preparing the water- and oil-repellent composition of the invention comprises at least one fluorine-containing aromatic ester oligomer. The oligomer comprises or consists essentially of (1) at least two repeat units derived or derivable from the reaction of at least one dicarboxylic acid (or a derivative thereof, for example, a dicarboxylic acid halide, a dicarboxylic acid anhydride, or a dicarboxylic acid ester) and at least one polyol, with the proviso that either the dicarboxylic acid (or derivative) or the polyol (or both) is aromatic or heteroaromatic and (2) fluorochemical endgroups derived or derivable from the reaction of (i) the dicarboxylic acid (or derivative) and at least one fluorine-containing monoalcohol or (ii) the polyol and at least one fluorine-containing monocarboxylic acid (or derivative).
Thus, the fluorochemical composition can comprise a single fluorine-containing aromatic ester oligomer having a certain number of the specified repeat units (a number greater than or equal to two; generally, a number in the range of 2 to about 20; preferably, 2 to 8; more preferably, 3 to 6; most preferably, 3 or 4) or it can comprise a mixture of such oligomers of varying numbers of repeat units. The composition can further contain fluorine-containing aromatic ester compounds having fewer than two such repeat or repeatable units, as well as one or more fluorine-free extenders or one or more conventional additives such as those described infra. Useful fluorine-free extender compounds include, for example, siloxanes, (meth)acrylate and substituted acrylate polymers and copolymers, N-methylolacrylamide-containing acrylate polymers, urethanes, blocked isocyanate-containing polymers and oligomers, condensates or precondensates of urea or melamine with formaldehyde, glyoxal resins, condensates of fatty acids with melamine or urea derivatives, condensates of fatty acids with polyamides and their epichlorohydrin adducts, waxes, polyethylene, chlorinated polyethylene, alkyl ketene dimers, esters, and amides, and mixtures thereof. The relative amount of extender compound to fluorine-containing oligomer is not critical. However, the overall fluorochemical composition generally contains, relative to the amount of solids present in the system, at least about 3 weight percent, preferably at least about 5 weight percent, carbon-bound fluorine in the form of fluorochemical groups.
Preferably, the composition comprises a mixture of aromatic ester molecules of varying structure, more preferably, a mixture of at least one aromatic ester oligomer (2 or more repeat units) and at least one aromatic ester compound (0 or 1 repeatable unit). Most preferably, the composition comprises a mixture of four different aromatic ester molecules, namely, those having 0, 1, 2, and 3 repeat or repeatable units (that is, a mixture of the two aromatic ester oligomers that have 2 and 3 repeat units, respectively, and the two aromatic ester compounds that have 0 and 1 repeatable unit, respectively).
Preferred classes of fluorine-containing aromatic ester oligomers are those represented by the following formulas
R1xe2x80x94Oxe2x80x94(Cxe2x95x90O)xe2x80x94Axe2x80x94(Cxe2x95x90O)xe2x80x94Oxe2x80x94[R2xe2x80x94Oxe2x80x94(Cxe2x95x90O)xe2x80x94Axe2x80x94(Cxe2x95x90O) xe2x80x94O]nxe2x80x94R1xe2x80x83xe2x80x83(I)
R1xe2x80x94Oxe2x80x94(Cxe2x95x90O)xe2x80x94R2xe2x80x94(Cxe2x95x90O)xe2x80x94Oxe2x80x94[Axe2x80x94Oxe2x80x94(Cxe2x95x90O)xe2x80x94R2xe2x80x94(Cxe2x95x90O)xe2x80x94O]nxe2x80x94R1xe2x80x83xe2x80x83(II)
R1xe2x80x94(Cxe2x95x90O) xe2x80x94Oxe2x80x94Axe2x80x94Oxe2x80x94(Cxe2x95x90O)xe2x80x94[R2xe2x80x94(Cxe2x95x90O) xe2x80x94Oxe2x80x94Axe2x80x94Oxe2x80x94(Cxe2x95x90O)]nxe2x80x94R1xe2x80x83xe2x80x83(III)
R1xe2x80x94(Cxe2x95x90O) xe2x80x94Oxe2x80x94R2xe2x80x94Oxe2x80x94(Cxe2x95x90O) xe2x80x94[Axe2x80x94(Cxe2x95x90O)xe2x80x94Oxe2x80x94R2xe2x80x94Oxe2x80x94(Cxe2x95x90O)]nxe2x80x94R1xe2x80x83xe2x80x83(IV)
(with those of Formulas I and IV being more preferred, and those of Formula I most preferred) wherein each R1 is independently the residue of at least one fluorine-containing monoalcohol or fluorine-containing monocarboxylic acid (or derivative); each A and each R2 independently comprises at least one aliphatic, heteroaliphatic, saturated alicyclic, saturated heteroalicyclic, aromatic, heteroaromatic, or polymeric moiety; and n is an integer of at least two; with the proviso that either A or R2 or both (preferably, A) comprises an aromatic or heteroaromatic moiety that is directly ring-bonded to the adjacent ester groups shown in Formulas I-IV. The aromatic or heteroaromatic moiety can comprise one or more rings (which can be fused or can be separated by one or more spacer groups, for example, an aliphatic group), and the adjacent ester groups can be bonded to a single ring or to separate rings of the aromatic or heteroaromatic moiety. The rings can be substituted with other groups that do not interfere with the reactivity of carboxylic acid or hydroxyl groups, do not cause undesirable side reactions, and do not cause decomposition of the resulting fluorochemical composition during use (for example, one or more halogen, alkyl, alkoxy, or aryl groups substituted for one or more ring-bonded hydrogen atoms). The polymeric moiety preferably has a number average molecular weight in the range of about 80 to about 2000 (more preferably, about 80 to about 1000).
Preferably, R1 comprises at least one fluorochemical group, Rf, that is fluoroaliphatic or fluoroalicyclic. More preferably, Rf contains a perfluorinated carbon chain having from 3 to about 20 carbon atoms (more preferably from about 4 to about 12 carbon atoms; most preferably, about 8 carbon atoms). A is preferably phenylene, napthalene, biphenylene, bis(phenylene)methylene, or bis(phenylene)propylidene (more preferably, phenylene; most preferably, meta- or para-phenylene). R2 is preferably a divalent aliphatic, saturated alicyclic, aromatic, aliphatic polyester, polydialkylsiloxane, or poly(oxyalkylene) moiety; more preferably, a divalent aliphatic, aromatic, aliphatic polyester, polydimethylsiloxane, or poly(oxyalkylene) moiety; even more preferably, hexylene, ethylene, propylene, neopentylene, ethyleneoxyethylene, bis(ethyleneoxycarbonyl)phenylene, polycaprolactone, polyoxyethylene, polyoxypropylene, or polydimethylsiloxane; most preferably, hexylene, ethylene, or propylene. n is generally an integer in the range of 2 to about 10; preferably, 2 to 8; more preferably, 3 to 6; most preferably, 3 to 4.
Preferred classes of fluorine-containing aromatic ester compounds are those that can be represented by Formulas I-IV above (more preferably, Formulas I and IV; most preferably, Formula I), wherein defined above.
The repellency-imparting, fluorochemical composition used in preparing the water- and oil-repellent composition of the invention can be prepared by using procedures and apparatus known to those skilled in the art of esterification and ester exchange reactions. For example, the fluorochemical composition can be prepared by (a) simultaneously reacting the fluorine-containing monoalcohol or monocarboxylic acid with the polyol and the dicarboxylic acid (or derivative); (b) first reacting the polyol with the dicarboxylic acid (or derivative), and then reacting the resulting mixture with the fluorine-containing monoalcohol or monocarboxylic acid; or (c) first reacting either the fluorine-containing monoalcohol with the dicarboxylic acid (or derivative) or the fluorine-containing monocarboxylic acid with the polyol, and then reacting the resulting mixture with the remaining reactant. Method (c) is generally preferred, because the probability of complete consumption of the fluorine-containing reactant can be higher than for Methods (a) and (b), and because it is believed that this method can produce a broader range of oligomers than Methods (a) and (b).
When a fluorine-containing monoalcohol is used to prepare fluorine-containing aromatic ester oligomers of Formulas I and II above, the molar ratio of monoalcohol to dicarboxylic acid can be in the range of about 1:1 to 1:10 (preferably, about 1:1 to 1:7; more preferably, about 1:1 to 1:2; and most preferably, about 1:1 to 1:1.5). The ratio of dicarboxylic acid to polyol can then be in the range of about 2:1 to 1:1. Preferably, the ratio of the total number of equivalents of hydroxyl groups to the total number of equivalents of carboxyl groups is about 1:1.
Similarly, when a fluorine-containing monocarboxylic acid is used to prepare fluorine-containing aromatic ester oligomers of Formulas III and IV above, the ratio of monocarboxylic acid to polyol can be in the range of about 1:1 to 1:10 (preferably, about 1:1 to 1:7; more preferably, about 1:1 to 1:2; and most preferably, about 1:1 to 1:1.5). The ratio of polyol to dicarboxylic acid can then be in the range of about 2:1 to 1:1, and the ratio of the total number of equivalents of hydroxyl groups to the total number of equivalents of carboxyl groups is preferably about 1:1.
The reactions can be carried out in solution or in the molten state (using commonly-used solvents and/or equipment), generally under atmospheric pressure and at temperatures sufficient to maintain the reactants in solution or in the melt. For example, temperatures in the range of about 100-240xc2x0 C. (preferably, about 115-210xc2x0 C.; more preferably, about 120-170xc2x0 C.) can generally be utilized. Removal of solvent or byproduct HCl, if present, can be conducted at reduced pressures, for example, using a vacuum equivalent to 508 mm Hg or less.
Fluorine-containing monoalcohols and monocarboxylic acids suitable for use in preparing the repellency-imparting, fluorochemical composition include those that comprise at least one of the above-described Rf groups. The Rf groups can contain straight chain, branched chain, or cyclic fluorinated alkylene groups or any combination thereof. The Rf groups can optionally contain catenary heteroatoms (that is, heteroatoms bonded to carbon atoms in the carbon-carbon chain so as to form a carbon-heteroatom-carbon chain) such as oxygen, divalent or hexavalent sulfur, or nitrogen. Fully-fluorinated groups are generally preferred, but hydrogen or chlorine atoms can also be present as substituents, provided that no more than one atom of either is present for every two carbon atoms. It is additionally preferred that any Rf group contain at least about 40% fluorine by weight, more preferably at least about 50% fluorine by weight. The terminal portion of the group is generally fully-fluorinated, preferably containing at least 7 fluorine atoms, e.g., CF3CF2CF2xe2x80x94, (CF3)2CFxe2x80x94, SF5CF2xe2x80x94. Perfluorinated aliphatic groups (i.e., those of the formula CnF2n+1xe2x80x94) are the most preferred Rf groups. Preferably, the fluorine-containing monoalcohols and monocarboxylic acids comprise at least one sulfonamido group, as this group appears to enhance the thermal stability of the resulting fluorochemical composition.
Useful fluorine-containing monoalcohols include (1) those having the general formula Rf(CH2)nCH2OH, wherein Rf is as defined above and n is an integer from 0 to about 20 (preferably from 0 to about 12, more preferably from zero to four, most preferably zero or one); (2) those having the general formula RfSO2N(R1)R2OH, wherein Rf is as defined above, R1 is hydrogen or a monovalent alkyl (straight chain or branched), cycloalkyl, or aryl radical having from 1 to about 12 carbon atoms (preferably from 1 to about 8 carbon atoms, more preferably from one to about four carbon atoms), and R2 is a divalent alkyl (straight chain or branched) or cycloalkyl radical having from 1 to about 12 carbon atoms (preferably from 1 to about 8 carbon atoms, more preferably from 1 to about 4 carbon atoms) and which can contain heteroatoms such as divalent oxygen, divalent sulfur, trivalent nitrogen, or hexavalent sulfur; (3) those having the general formula RfQR2OH, wherein Rf is as defined above, Q is xe2x80x94CON(R1)xe2x80x94, xe2x80x94SO2xe2x80x94, or carbonyl, and R1 and R2 are as defined above; and (4) those having the general formula RfR2XR2OH, wherein Rf is as defined above, each R2 is independently selected from the group defined above for R2, and X is divalent oxygen or sulfur or xe2x80x94N(R1)xe2x80x94, where R1 is as defined above.
Representative examples of useful fluorine-containing monoalcohols include:
CF3(CF2)3SO2N(CH3)CH2CH2OH,
CF3(CF2)3SO2N(CH3)CH(CH3)CH2OH,
CF3(CF2)3SO2N(CH3)CH2CH(CH3)OH,
CF3(CF2)3SO2N(CH2CH3)CH2CH2OH,
C6F13SO2N(CH3)(CH2)4OH,
CF3(CF2)7SO2N(H)(CH2)3OH,
CF3(CF2)7SO2N(CH3)CH2CH2OH,
CF3(CF2)7SO2N(CH3)(CH2)4OH,
C8F17SO2N(CH3)(CH2)11OH,
CF3(CF2)7SO2N(CH2CH3)CH2CH2OH,
CF3(CF2)7SO2N(C2H5)(CH2)6OH,
CF3(CF2)7SO2N(C2H5)(CH2)11OH,
CF3(CF2)6SO2N(C3H7)CH2OCH2CH2CH2OH,
CF3(CF2)7SO2N(CH2CH2CH3)CH2CH2OH,
CF3(CF2)9SO2N(CH2CH2CH3)CH2CH2OH,
CF3(CF2)7SO2N(C4H9)CH2CH2OH,
CF3(CF2)7SO2N(C4H9)(CH2)4OH,
2-[N-methyl-2-(4-perfluoro-(2,6-diethylmorpholinyl))perfluoroethylsulfonamido]ethanol,
C7F15CON(CH3)CH2CH2OH,
C7F15CON(C2H5)CH2CH2OH,
C8F17CON(C2H5)CH2CH2OH,
C8F17CON(CH3)(CH2)11OH,
C2F5O(C2F4O)3CF2CONHC2H4OH,
Rf[OCF(CF3)CF2]1-6 OCF(CF3)CH2OH
CF3CF(CF2Cl)(CF2CF2)6CF2CON(CH3)CH2CH2OH,
CF3(CF2)6SO2CH2CH2OH,
CF3(CF2)7SO2CH2CH2OH,
C5F11COOCH2CH2OH,
CF3(CF2)6COOCH2CH2OH,
C8F17COOCH2CH2OH,
C8F17 (CH2)11N(C2H5)CH2CH2OH,
C3F7CH2OH,
CF3(CF2)6CH2OH,
CF3(CF2)6CH2CH2CH2OH,
CF3(CF2)7CH2CH2OH,
CF3(CF2)7CH2CH2SO2N(CH3)CH2CH2OH,
CF3(CF2)5CH2CH2SO2N(CH3)CH2CH2OH,
CF3(CF2)3CH2CH2SO2N(CH3)CH2CH2OH,
CF3(CF2)7CH2CH2CH2OH,
CF3(CF2)7(CH2)11CH2OH,
CF3C(CF2H)F(CF2)10(CH2)2OH,
CF3C(CF2Cl)F(CF2)10(CH2)2OH,
Rf(CH2)2S(CH2)2OH,
Rf(CH2)4S(CH2)2OH,
Rf(CH2)2S(CH2)3OH,
Rf(CH2)2SCH(CH3)CH2OH,
Rf(CH2)4SCH(CH3)CH2OH,
RfCH2CH(CH3)S(CH2)2OH,
Rf(CH2)2S(CH2)11OH,
Rf(CH2)2S(CH2)3O(CH2)2OH,
Rf(CH2)3O(CH2)2OH,
Rf(CH2)3SCH(CH3)CH2OH, and the like, and mixtures thereof, wherein Rf is a perfluoroalkyl group of 3-16 carbon atoms. If desired, rather than using such alcohols, similar thiols can be utilized.
Preferred fluorine-containing monoalcohols include 1,1-dihydroperfluorooctanol, 1,1,2,2-tetrahydroperfluorodecanol, 1,1,2,2,3,3-hexahydroperfluorodecanol, 2-(N-ethylperfluorooctanesulfonamido)ethanol (EtFOSE), 2-(N-methylperfluorooctanesulfonamido)ethanol (MeFOSE), 2-(N-butylperfluorooctanesulfonamido)ethanol (BuFOSE), 2-(N-ethylperfluorobutanesulfonamido)ethanol, 2-(N-methylperfluorobutanesulfonamido)ethanol, 2-(N-n-propylperfluorodecanesulfonamido)ethanol, N-ethyl-N-(2-hydroxyethyl) perfluoroheptanamide, Zonyl(trademark) BA fluorochemical telomer alcohol (DuPont Chemicals; Wilmington, Del.), and the like, and mixtures thereof.
Useful fluorine-containing monocarboxylic acids include (1) those having the formula Rf(CH2)n(X)p(CH2)mCOOH, wherein Rf is as defined above, n and m are independently integers of 0 to 14 (preferably 0-8, more preferably 0-4), X is divalent oxygen or sulfur, and p is an integer of 0 or 1, and (2) those having the formula RfQRxe2x80x2COOH, wherein Rf is as defined above, Rxe2x80x2 is a divalent alkyl (straight chain or branched) or cycloalkyl radical having from 1 to about 12 carbon atoms (preferably from 1 to about 8 carbon atoms, more preferably from 1 to about 4 carbon atoms), and the divalent linking group Q is xe2x80x94SO2N(Rxe2x80x3)xe2x80x94 or xe2x80x94CON(Rxe2x80x3)xe2x80x94 wherein Rxe2x80x3 is a monovalent alkyl (straight chain or branched), cycloalkyl, or aryl radical having from 1 to about 12 carbon atoms (preferably from 1 to about 8 carbon atoms, more preferably from 1 to about 4 carbon atoms).
Representative examples of useful fluorine-containing monocarboxylic acids include perfluorobutanoic (C3F7COOH), perfluoroisobutanoic ((CF3)2CFCOOH), hydroperfluorobutanoic (C3F6HCOOH), perfluoropentanoic (C4F9COOH), hydroperfluoropentanoic (C4F8HCOOH), perfluorohexanoic (C F11COOH), hydroperfluorohexanoic (C5F10HCOOH), perfluorcyclohexanyl carboxylic (C6F11COOH), perfluoroheptanoic (C6F13COOH), perfluorooctanoic (C7F15COOH), perfluorononanoic (C8F17COOH), omega-hydroperfluorononanoic (C8F16HCOOH), perfluorodecanoic (C9F19COOH), omega-hydroperfluoroundecanoic (C10F20HCOOH), perfluorodoecanoic (C11F23COOH), perfluorotetradecanoic (C13F27COOH), perfluorohexadecanoic (C15F31COOH), perfluorobicyclo(4.2.0)-3H-4-octanoic acid, 2-perfluorooctylacetic, 5-perfluoroheptypentanoic, 11-perfluoroheptylundecanoic, perfluoro(3-ethoxypropionic), perfluoro(3-propoxypropionic), perfluoro(3-butoxypropionic), perfluoro(3-pentoxypropionic), perfluoro(3-hexoxypropionic), perfluoro(3-heptoxypropionic), Rf[OCF(CF3)CF2]1-6 OCF(CF3)COOH where Rf is a perfluroalkyl group of 3-16 carbon atoms perfluoro(3-octoxypropionic), 12-perfluoroisopropoxyperfluorododecanoic, 3-(3-perfluoroheptylpropoxy)propanoic, 3-(3-perfluoroheptylpropylthio)propanoic, 4-(8-perfluoroisopropoxyperfluorooctyl)butanoic, 4-(4-perfluoroisopropoxyperfluorobutyl)butanoic, 4-(6-bis(perfluoroisopropyl)fluoromethoxyperfluorohexyl)buta noic, 12-(16-bis(perfluoroisopropyl)fluoromethoxy)perfluorohexadecyl)dodecanoic, 4-(bis(perfluoroisopropyl)fluoromethoxy)perfluorobutanoic, 12-(2-perfluoroisopropoxyperfluoroethyl)dodecanoic, 6-(2-perfluorocyclobutoxyperfluoroethyl)hexanoic, 4-(bis(perfluoroisopropyl)fluoromethoxy)perfluorobutanoic, 4-(2-bis(perfluoroisopropyl)fluoromethoxyperfluoroethyl)buta noic, 11-(N-methyl)perfluoroheptanecarboxamido)undecanoic, 2-(N-(ethyl)perfluorooctanesulfonamido)acetic, 2-(N-(ethyl)perfluorohexanesulfonamido)acetic, 2-(N-(ethyl)perfluorobutanesulfonamido)acetic 2-(N-(ethyl)perfluorodecanesulfonamido)acetic, 2-(N-(ethyl)perfluorododecanesulfonamido)acetic, 2-(N-(methyl)perfluorooctanesulfonamido)acetic, and 2-(N-(methyl)perfluorobutanesulfonamido)acetic, and the like, and mixtures thereof.
Preferred fluorine-containing monocarboxylic acids include 2-(N-(ethyl)perfluorooctanesulfonamido)acetic, 2-(N-(ethyl)perfluorohexanesulfonamido)acetic, 2-(N-(ethyl)perfluorobutanesulfonamido)acetic 2-(N-(ethyl)perfluorododecanesulfonamido)acetic, 2-(N-(methyl)perfluorooctanesulfonamido)acetic, 2-(N-(methyl)perfluorobutanesulfonamido)acetic, 2-perfluorooctylacetic, perfluorooctanoic (C7F15COOH), perfluorononanoic (C8F17COOH), and the like, and mixtures thereof.
Most preferred fluorine-containing monoalcohols and monocarboxylic acids include 2-(N-ethylperfluorooctanesulfonamido)ethanol (EtFOSE), 2-(N-methylperfluorooctanesulfonamido)ethanol (MeFOSE), 2-(N-butylperfluorooctanesulfonamido)ethanol (BuFOSE), 2-(N-methylperfluorobutanesulfonamido)ethanol, 2-(N-(ethyl)perfluorooctanesulfonamido)acetic acid, and mixtures thereof. If desired, monoalcohol(s) or monocarboxylic acid(s) that are not fluorine-containing can be utilized in addition to the fluorine-containing monoalcohol(s) or monocarboxylic acid(s) as a portion of the total monoalcohol or monocarboxylic acid charge (for example, in amounts up to about 50 mole percent of the total or even higherxe2x80x94for example, as high as about 75 mole percent).
Dicarboxylic acids and derivatives thereof (for example, dicarboxylic acid halides, dicarboxylic acid anhydrides, and dicarboxylic acid esters) suitable for use in preparing the repellency-imparting, fluorochemical composition include those that comprise at least one aliphatic, heteroaliphatic (that is, containing in-chain heteroatoms, such as nitrogen, oxygen, or sulfur), saturated alicyclic, saturated heteroalicyclic, aromatic, heteroaromatic, or polymeric moiety. The dicarboxylic acids can optionally contain one or more xe2x80x9cnon-interferingxe2x80x9d groups (groups that do not interfere with the reactivity of the carboxylic acid groups, do not cause undesirable side reactions, and do not cause decomposition of the resulting fluorochemical composition), for example, alkyl, sulfonate, ester, ether, halo, haloalkyl, amide, or carbamate groups. Preferably, the dicarboxylic acids (or derivatives) are aromatic or aliphatic in nature, more preferably, aromatic.
Dicarboxylic acid derivatives are sometimes preferred over dicarboxylic acids for a variety of reasons. For example, acid halides provide both relatively fast reaction rates and reactions that tend to go to completion. The resulting HCl is volatile and can be removed under vacuum or by other removal means, such as by water washing.
For applications in which evolution of HCl is undesirable, a lower alkyl ester of a dicarboxylic acid can be used. Use of such lower alkyl esters can facilitate processing, due to their lower melting points and greater solubility in some solvents (relative to the corresponding acids). Continuous removal of the resulting lower alkyl alcohol can be employed to bring the reaction to completion. A catalyst can also be used and can be selected so as to be removable or deactivatable after reaction is complete, or so as to cause minimal decomposition of the resulting fluorochemical composition under use conditions.
Anhydrides can also be used. Particularly useful anhydride derivatives of dicarboxylic acids are cyclic anhydrides, which react relatively rapidly with an alcohol to form an ester and a carboxylic acid group. This allows a preponderance of monoester/monocarboxylic acid to be formed from the reaction of the cyclic anhydride with one alcohol (such as the fluorine-containing monoalcohol), followed by reaction of the remaining carboxylic acid groups with a second alcohol (such as the polyol). Alternatively, the remaining carboxylic acid groups can first be converted to the corresponding acid halide and then reacted with the second alcohol.
Representative examples of suitable dicarboxylic acids and dicarboxylic acid derivatives include the following acids and their corresponding esters, halides, and anhydrides: terephthalic; isophthalic; t-butylisophthalic; 5-chloro-1,3-benzenedicarboxylic; tetrachlorophthalic; phthalic; any of the isomeric naphthalene dicarboxylic acids such as 1,4-, 2,6-, 2,5-, and 2,7-naphthalenedicarboxylic; 5-sulfoisophthalic; 2-sulfoterephthalic; 5-sulfonaphthalene-1,4-dicarboxylic; sulfofluorenedicarboxylic acids such as 9,9-di(2xe2x80x2-carboxyethyl)-fluorene-2-sulfonic acid; 2,2xe2x80x2- and 4,4xe2x80x2-biphenyldicarboxylic; 2,4-, 2,5-, and 2,6-pyridinedicarboxylic; 2,6-dimethyl-3,5-pyridinedicarboxylic; 2-methyl-3,4-quinolinedicarboxylic; 3,4-furandicarboxylic; 2,3-indoledicarboxylic; 4,4xe2x80x2-benzophenone dicarboxylic; 4,4xe2x80x2-diphenylmethanedicarboxylic; 4,4xe2x80x2-diphenylether dicarboxylic; 4,4xe2x80x2-diphenylthioether dicarboxylic; 4,4xe2x80x2-diphenylamine dicarboxylic; 4,4xe2x80x2-diphenylsulfone dicarboxylic; chelidonic; azelaic; maleic; fumaric; itaconic; phenylenediacetic; 2,5-tetrahydrofuranedicarboxylic; 1,5-pent-2-enedioic; adipic; 2-methyleneadipic; 3-methylitaconic; 3,3-dimethylitaconic; sebacic; suberic; pimelic; succinic; benzylsuccinic; sulfosuccinic; gluratic; 2-methyleneglutaric; 2-sulfoglutaric; 3-sulfoglutaric; diglycolic; dilactic; 3,3xe2x80x2-(ethylenedioxy)dipropionic; dodecanedioic; 2-sulfododecanedioic; decanedioic; undecanedicarboxylic; hexadecanedicarboxylic; dimerized fatty acids (such as those obtained by the dimerization of olefinically unsaturated monocarboxylic acids containing 16 to 20 carbon atoms, for example, oleic acid and linoleic acid and the like); 1,2-, 1,4-, and 1,6-cyclohexanedicarboxylic; norbornenedicarboxylic; bi-cyclooctanedicarboxylic; and other aliphatic, heteroaliphatic, aromatic, heteroaromatic, saturated alicyclic, or saturated heteroalicyclic dicarboxylic acids; and the like; and mixtures thereof. Salts (for example, alkali metal salts) of the above-described sulfonic acids can also be used.
Preferred dicarboxylic acids and dicarboxylic acid derivatives include terephthalic, isophthalic, phthalic, 1,4-, 2,5-, 2,6-, and 2,7-naphthalenedicarboxylic, 4,4xe2x80x2-diphenylmethanedicarboxylic, succinic, adipic, pimelic, suberic, and sebacic acids (and derivatives thereof), and the like, and mixtures thereof; with isophthalic, terephthalic, and adipic acids (and derivatives thereof), and mixtures thereof being more preferred. When a non-aromatic polyol is used, the above-cited aromatic dicarboxylic acids (and derivatives thereof) are generally preferred, with isophthalic acid, terephthalic acid, isophthaloyl chloride, terephthaloyl chloride, dimethylisophthalate, dimethylterephthalate, and mixtures thereof being more preferred (due to their good polyester compatibility). When an aromatic polyol is used, the above-cited aliphatic dicarboxylic acids (and derivatives thereof) are generally preferred, with adipic acid and adipoyl chloride (and mixtures thereof) being more preferred.
Polyols suitable for use in preparing the repellency-imparting, fluorochemical composition include those organic polyols that have an average hydroxyl functionality of at least about 2 (preferably, about 2 to 5; more preferably, about 2 to 3; most preferably, about 2, as diols are most preferred). The hydroxyl groups can be primary or secondary, with primary hydroxyl groups being preferred for their greater reactivity. Mixtures of diols with polyols that have an average hydroxyl functionality of about 2.5 to 5 (preferably about 3 to 4; more preferably, about 3) can be used. It is preferred that such mixtures contain no more than about 50 percent by weight of such polyols, more preferably no more than about 30 percent, and most preferably no more than about 10 percent. Preferred mixtures are mixtures of diols and triols.
Suitable polyols include those that comprise at least one aliphatic, heteroaliphatic, saturated alicyclic, saturated heteroalicyclic, aromatic, heteroaromatic, or polymeric moiety. Preferred polyols are aliphatic or polymeric polyols that contain hydroxyl groups as terminal groups or as groups that are pendant from the backbone chain of the polyol. The molecular weight (that is, the number average molecular weight) of the polyol can generally vary from about 60 to about 2000 (preferably, from about 60 to about 1000; more preferably, from about 60 to about 500; most preferably, from about 60 to about 300), and its equivalent weight (that is, the number average equivalent weight) generally can be in the range of about 30 to about 1000 (preferably, from about 30 to about 500; more preferably, from about 30 to about 250). (Polyols of higher equivalent weight may have a tendency to reduce the repellency provided by the fluorochemical composition). Preferred polyols are substantially free of thermally unstable groups and do not decompose or liberate volatile components at temperatures below about 100xc2x0 C.
Representative examples of suitable non-polymeric polyols include alkylene glycols (for example, 1,2-ethanediol, 1,2-propanediol, 3-chloro-1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol (neopentylglycol), 2-ethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 1,5-pentanediol, 2-ethyl-1,3-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 3-methyl-1,5-pentanediol, 1,2-, 1,5-, and 1,6-hexanediol, 2-ethyl-1,6-hexanediol, bis(hydroxymethyl)cyclohexane, 1,8-octanediol, bicyclo-octanediol, 1,10-decanediol, tricyclo-decanediol, norbornanediol, and 1,18-dihydroxyoctadecane); polyhydroxyalkanes (for example, glycerine, trimethylolethane, trimethylolpropane, 2-ethyl-2-(hydroxymethyl)-1,3-propanediol, 1,2,6-hexanetriol, pentaerythritol, quinitol, mannitol, and sorbitol); and other polyhydroxy compounds such as diethylene glycol, triethylene glycol, tetraethylene glycol, tetramethylene glycol, dipropylene glycol, diisopropylene glycol, tripropylene glycol, 1,11-(3,6-dioxaundecane)diol, 1,14-(3,6,9,12-tetraoxatetradecane)diol, 1,8-(3,6-dioxa-2,5,8-trimethyloctane)diol, 1,14-(5,10-dioxatetradecane)diol, castor oil, 2-butyne-1,4-diol, N,N-bis(hydroxyethyl)benzamide, 4,4xe2x80x2-bis(hydroxymethyl)diphenylsulfone, 1,4-benzenedimethanol, 1,3-bis(2-hydroxyethyoxy)benzene, 1,2-, 1,3-, and 1,4-resorcinol, 1,6-, 2,6-, 2,5-, and 2,7-dihydroxynaphthalene, 2,2xe2x80x2- and 4,4xe2x80x2-biphenol, 1,8-dihydroxybiphenyl, 2,4-dihydroxy-6-methyl-pyrimidine, 4,6-dihydroxypyrimidine, 3,6-dihydroxypyridazine, bisphenol A, 4,4xe2x80x2-ethylidenebisphenol, 4,4xe2x80x2-isopropylidenebis(2,6-dimethylphenol), bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane (bisphenol C), 1,4-bis(2-hydroxyethyl)piperazine, bis(4-hydroxyphenyl) ether, as well as other aliphatic, heteroaliphatic, saturated alicyclic, aromatic, saturated heteroalicyclic, and heteroaromatic polyols, and the like, and mixtures thereof.
Representative examples of useful polymeric polyols include polyoxyethylene, polyoxypropylene, and ethylene oxide-terminated polypropylene glycols and triols of molecular weights from about 200 to about 2000, corresponding to equivalent weights of about 100 to about 1000 for the diols or about 70 to about 700 for triols; polytetramethylene glycols of varying molecular weight; polydialkylsiloxane diols of varying molecular weight; hydroxy-terminated polyesters and hydroxy-terminated polylactones (e.g., polycaprolactone polyols); hydroxy-terminated polyalkadienes (e.g., hydroxyl-terminated polybutadienes); and the like. Mixtures of polymeric polyols can be used if desired.
Useful commercially available polymeric polyols include Carbowax(trademark) poly(ethylene oxide) materials in the number average molecular weight (Mn) range of about 200 to about 2000 (available from Union Carbide Corp.); poly(propylene oxide) materials such as PPG-425 (available from Lyondell Chemicals); Bisphenol A ethoxylate, Bisphenol A propyloxylate, and Bisphenol A propoxylate/ethoxylate (available from Sigma-Aldrich); polytetramethylene ether glycols such as Polymeg(trademark) 650 and 1000 (available from Quaker Oats Company) and the Terathane(trademark) polyols (available from DuPont); hydroxyl-terminated polybutadiene resins such as the Poly bd(trademark) materials (available from Elf Atochem); the xe2x80x9cPePxe2x80x9d series (available from Wyandotte Chemicals Corporation) of polyoxyalkylene tetrols having secondary hydroxyl groups, for example, xe2x80x9cPePxe2x80x9d 450, 550, and 650; polycaprolactone polyols with Mn in the range of about 200 to about 2000 such as Tone(trademark) 0201, 0210, 0301, and 0310 (available from Union Carbide); xe2x80x9cParaplex(trademark) U-148xe2x80x9d (available from Rohm and Haas), an aliphatic polyester diol; polyester polyols such as the Multron(trademark) poly(ethyleneadipate)polyols (available from Mobay Chemical Co.); polycarbonate diols such as Duracarb(trademark) 120, a hexanediol carbonate with Mn=900 (available from PPG Industries Inc.); and the like; and mixtures thereof.
Preferred polyols include 1,2-ethanediol; 1,2- and 1,3-propanediol; 1,3- and 1,4-butanediol; neopentylglycol; 1,5-pentanediol; 3-methyl-1,5-pentanediol; 1,2-, 1,5-, and 1,6-hexanediol; bis(hydroxymethyl)cyclohexane; 1,8-octanediol; 1,10-decanediol; di(ethylene glycol); tri(ethylene glycol); tetra(ethylene glycol); di(propylene glycol); di(isopropylene glycol); tri(propylene glycol); polyoxyethylene diols (number average molecular weight of about 200 to about 1500); polyoxypropylene diols (number average molecular weight of about 200 to about 500); polycaprolactone diols (number average molecular weight of about 200 to about 600); resorcinol; hydroquinone; 1,6-, 2,5-, 2,6-, and 2,7-dihydroxynaphthalene; 4,4xe2x80x2-biphenol; bisphenol A; bis(4-hydroxyphenyl)methane; and the like; and mixtures thereof. More preferred are 1,2-ethanediol; 1,2- and 1,3-propanediol; neopentylglycol; 1,2- and 1,6-hexanediol; di(ethylene glycol); poly[di(ethylene glycol) phthalate] diol (having number average molecular weights of, for example, about 350 or about 575); poly(ethylene glycol) diols (having number average molecular weights of, for example, about 200, 300, 400, 600, 900, or 1450); polydimethylsiloxane diol; polypropylene glycol (having a number average molecular weight of, for example, about 425); dimer diol; polycaprolactone diol (having a number average molecular weight of, for example, about 530); bisphenol A; resorcinol; hydroquinone; and mixtures thereof. When non-aromatic dicarboxylic acids are used, the above-cited aromatic polyols are generally preferred, with resorcinol, hydroquinone, and bisphenol A being more preferred, due to their good polyester compatibility.
If desired for particular applications, small amounts of one or more polymeric or non-polymeric chain extenders (for example, diamines) can be utilized, in addition to the above-described reactants, in preparing the fluorochemical composition.
Treatable Substrates
Substrates that can be treated with the above-described repellency-imparting fluorochemical composition to form the water- and oil-repellent composition of the invention generally comprise at least one material selected from the group consisting of synthetic and naturally-occurring organic or inorganic polymers (or the reactive precursors thereof, for example, mono- or multifunctional monomers or oligomers), ceramics, glasses, and ceramic/polymer composites or ceramers (or the reactive precursors thereof); with the proviso that, when the treatable substrate comprises a mixture of at least two polymers, the mixture is non-stratifying. (Stratification is undesirable because the fluorochemical composition may accumulate at the interface of or between the resulting polymer layers, rather than reaching the air interface in substantial quantity.) The substrates can further comprise one or more other materials (for example, metal fibers or fillers such as carbon black or titanium dioxide). All such substrates are suitable for topical treatment.
Suitable synthetic polymers (which can be either thermoplastic or thermoset) include commodity plastics such as, for example, poly(vinyl chloride), polyethylenes (high density, low density, very low density), polypropylene, and polystyrene; engineering plastics such as, for example, polyesters (including, for example, poly(ethylene terephthalate) and poly(butylene terephthalate)), polyamides (aliphatic, amorphous, aromatic), polycarbonates (for example, aromatic polycarbonates such as those derived from bisphenol A), polyoxymethylenes, polyacrylates and polymethacrylates (for example, poly(methyl methacrylate)), some modified polystyrenes (for example, styrene-acrylonitrile (SAN) and acrylonitrile-butadiene-styrene (ABS) copolymers), high-impact polystyrenes (SB), fluoroplastics, and blends such as poly(phenylene oxide)-polystyrene and polycarbonate-ABS; high-performance plastics such as, for example, liquid crystalline polymers (LCPs), polyetherketone (PEEK), polysulfones, polyimides, and polyetherimides; thermosets such as, for example, alkyd resins, phenolic resins, amino resins (for example, melamine and urea resins), epoxy resins, unsaturated polyesters (including so-called vinyl esters), polyurethanes, allylics (for example, polymers derived from allyldiglycolcarbonate), fluoroelastomers, and polyacrylates; and the like and blends thereof. Suitable naturally occurring polymers include proteinaceous materials such as silk, wool, and leather; and cellulosic materials.
Thermoplastic and thermoset polymers, including those described above, are preferred treatable substrates, as such polymers can either be topically treated with the fluorochemical composition or can be combined with it (in bulk) to form a blend. Thermoplastic polymers are more preferred in view of their melt processability. Preferably, the thermoplastic polymers are melt processable at elevated temperatures, for example, above about 150xc2x0 C. (more preferably, above about 250xc2x0 C.; even more preferably, above about 280xc2x0 C.; most preferably, above about 290xc2x0 C.). Preferred thermoset polymers include polyurethanes, epoxy resins, fluoroelastomers, polyacrylates, polymethacrylates, unsaturated polyesters, and blends thereof. Preferred thermoplastic polymers include, for example, polypropylene, polyethylene, polyacrylates, polymethacrylates, copolymers of ethylene and one or more alpha-olefins (for example, poly(ethylene-butene) and poly(ethylene-octene)), polyesters, polyurethanes, polycarbonates, polyetherimides, polyimides, polyetherketones, polysulfones, polystyrenes, ABS copolymers, polyamides, fluoroplastics, and blends thereof. More preferred are polypropylene, polyethylene, polyesters, poly(ethylene-octene), polyurethanes, polycarbonates, polyamides, and blends thereof, with polyesters, polycarbonates, polyurethanes, polyamides, and blends thereof being most preferred.
Preparation and Use of Composition
Preferably, the water- and oil-repellent composition of the invention can be prepared by (a) combining the repellency-imparting, fluorochemical composition and at least one thermoplastic polymer (optionally, along with other additives) and then melt processing the resulting combination; or (b) combining the repellency-imparting, fluorochemical composition and at least one thermosetting polymer or ceramer or the reactive precursors thereof (optionally, along with other additives) and then allowing the resulting combination to cure, optionally with the application of heat or actinic radiation. Alternative processes for preparing the water- and oil-repellent composition of the invention include, for example, (c) applying the repellency-imparting, fluorochemical composition to at least a portion of at least one surface of at least one treatable substrate; (d) dissolving the repellency-imparting, fluorochemical composition and at least one treatable substrate in at least one solvent and then casting or coating (for example, on a substrate such as wood or stone) the resulting solution and allowing evaporation of the solvent, optionally with the application of heat; and (e) combining the repellency-imparting, fluorochemical composition and at least one monomer (optionally, along with other additives) and then allowing polymerization of the monomer to occur, optionally in the presence of at least one solvent and optionally with the application of heat or actinic radiation.
To form a melt blend by melt processing, the fluorochemical composition can be, for example, intimately mixed with pelletized or powdered polymer and then melt processed by known methods such as, for example, molding, melt blowing, melt spinning, or melt extrusion. The fluorochemical composition can be mixed directly with the polymer or it can be mixed with the polymer in the form of a xe2x80x9cmaster batchxe2x80x9d (concentrate) of the fluorochemical composition in the polymer. If desired, an organic solution of the fluorochemical composition can be mixed with powdered or pelletized polymer, followed by drying (to remove solvent) and then by melt processing. Alternatively, the fluorochemical composition can be injected into a molten polymer stream to form a blend immediately prior to, for example, extrusion into fibers or films or molding into articles.
After melt processing, an annealing step can be carried out to enhance the development of repellent characteristics. In addition to, or in lieu of, such an annealing step, the melt processed combination (for example, in the form of a film or a fiber) can also be embossed between two heated rolls, one or both of which can be patterned. An annealing step typically is conducted below the melt temperature of the polymer (for example, in the case of polyamide, at about 150-220xc2x0 C. for a period of about 30 seconds to about 5 minutes).
The fluorochemical composition can be added to thermoplastic or thermosetting polymer (or, alternatively, to other treatable substrate materials) in amounts sufficient to achieve the desired repellency properties for a particular application. The amounts can be determined empirically and can be adjusted as necessary or desired to achieve the repellency properties without compromising the properties of the polymer (or other treatable substrate material). Generally, the fluorochemical composition can be added in amounts ranging from about 0.1 to about 10 percent by weight (preferably, from about 0.5 to about 4 percent; more preferably, from about 0.75 to about 2.5 percent) based on the weight of polymer (or other treatable substrate material).
In topical treatment of a treatable substrate, the fluorochemical composition can be employed alone or in the form of aqueous suspensions, emulsions, or solutions, or as organic solvent (or organic solvent/water) solutions, suspensions, or emulsions. Useful organic solvents include chlorinated hydrocarbons, alcohols (for example, isopropyl alcohol), esters, ketones (for example, methyl isobutyl ketone), and mixtures thereof. Generally, the solvent solutions can contain from about 0.1 to about 50 percent, or even up to about 90 percent, by weight non-volatile solids (based on the total weight of the components). Aqueous suspensions, emulsions, or solutions are generally preferred and generally can contain a non-volatile solids content of about 0.1 to about 50 percent, preferably, about 1 to about 10 percent, by weight (based on the total weight of the components). Alternatively, however, topical treatment can be carried out by applying (to at least a portion of at least one surface of at least one treatable substrate) a fluorochemical composition that comprises at least one fluorine-containing aromatic ester oligomer that is liquid at the use or treatment temperature. Such a topical treatment process can involve the use of the neat fluorochemical composition, without added solvent, and is thus preferred from an environmental perspective over the use of organic solvent solutions of the fluorochemical composition.
The topical treatment compositions comprising the fluorochemical composition can be applied to a treatable substrate by standard methods such as, for example, spraying, padding, dipping, roll coating, brushing, or exhaustion (optionally followed by the drying of the treated substrate to remove any remaining water or solvent). The treatable substrate can be in the form of molded or blown articles, sheets, fibers (as such or in aggregated form, for example, yarn, toe, web, or roving, or in the form of fabricated textiles such as carpets), woven and nonwoven fabrics, films, etc. If desired, the fluorochemical composition can be co-applied with conventional fiber treating agents, for example, spin finishes or fiber lubricants.
The topical treatment compositions can be applied in an amount sufficient to achieve the desired repellency properties for a particular application. This amount can be determined empirically and can be adjusted as necessary or desired to achieve the repellency properties without compromising the properties of the treatable substrate.
Any of a wide variety of constructions can be made from the water- and oil-repellent composition of the invention, and such constructions will find utility in any application where some level of repellency characteristics is required. For example, the composition of the invention can be used to prepare films and molded or blown articles, as well as fibers (for example, melt-blown or melt-spun fibers, including microfibers and sheath-core fibers) that can be used to make woven and nonwoven fabrics. Such films, molded or blown articles, fibers, and fabrics exhibit water and oil repellency (and soil resistance) characteristics under a variety of environmental conditions and can be used in a variety of applications.
For example, molded articles comprising the composition of the invention can be prepared by standard methods (for example, by high temperature injection molding) and are particularly useful as, for example, headlamp covers for automobiles, lenses (including eyeglass lenses), casings or circuit boards for electronic devices (for example, computers), screens for display devices, windows (for example, aircraft windows), and the like. Films comprising the composition of the invention can be made by any of the film making methods commonly employed in the art. Such films can be nonporous or porous (the latter including films that are mechanically perforated), with the presence and degree of porosity being selected according to the desired performance characteristics. The films can be used as, for example, photographic films, transparency films for use with overhead projectors, tape backings, substrates for coating, and the like.
Fibers comprising the composition of the invention can be used to make woven or nonwoven fabrics that can be used, for example, in making medical fabrics, medical and industrial apparel, fabrics for use in making clothing, home furnishings such as rugs or carpets, paper machine clothing, and filter media such as chemical process filters or respirators. Nonwoven webs or fabrics can be prepared by processes used in the manufacture of either melt-blown or spunbonded webs. For example, a process similar to that described by Wente in xe2x80x9cSuperfine Thermoplastic Fibers,xe2x80x9d Indus. Eng""g Chem. 48, 1342 (1956) or by Wente et al. in xe2x80x9cManufacture of Superfine Organic Fibers,xe2x80x9d Naval Research Laboratories Report No. 4364 (1954) can be used. Multi-layer constructions made from nonwoven fabrics enjoy wide industrial and commercial utility, for example, as medical fabrics. The makeup of the constituent layers of such multi-layer constructions can be varied according to the desired end-use characteristics, and the constructions can comprise two or more layers of melt-blown and spunbonded webs in many useful combinations such as those described in U.S. Pat. Nos. 5,145,727 (Potts et al.) and 5,149,576 (Potts et al.), the descriptions of which are incorporated herein by reference. In multi-layer constructions, the fluorochemical composition can be used alone in one or more layers or can be used in combination with other additive(s) in one or more layers. Alternatively, the fluorochemical composition and the other additive(s) can each be independently segregated in one or more layers. For example, in a spunbonded/melt-blown/spunbonded (xe2x80x9cSMSxe2x80x9d) three-layer construction, the other additive(s) (for example, antistats) can be used in one or both spunbonded layers, and the fluorochemical composition can be used in the melt-blown layer, to impart both antistatic and repellency characteristics to the overall construction.
The repellency-imparting, fluorochemical composition used in the composition of the invention can also find utility as an additive to coatings (for example, non-stratifying polymer or ceramer coatings). Such coatings can be water- and oil-repellent, and scratch-resistant (as well as soil-resistant) and can be used in the photographic industry or as protective coatings for optical or magnetic recording media.
If desired, the water- and oil-repellent composition of the invention can further contain one or more additives, including those commonly used in the art, for example, dyes, pigments, antioxidants, ultraviolet stabilizers, flame retardants, surfactants, plasticizers, tackifiers, fillers, and mixtures thereof. In particular, performance enhancers (for example, polymers such as polybutylene) can be utilized to improve the repellency characteristics in, for example, melt additive polyolefin applications.
Objects and advantages of this invention are further illustrated by the following examples, but the particular materials and amounts thereof recited in these examples, as well as other conditions and details, should not be construed to unduly limit this invention. In the examples, where weight percent or parts by weight are indicated, these are based on the weight of the entire composition unless indicated otherwise.